Honing tool having fullfloating body



Sept. 5, 1961 J. H. GREENING ET AL 2,998,582

HONING TOOL HAVING FULL-FLOATING BODY 2 Sheets-Sheet Filed May 12, 1958 2 Q mm PM w r w m 5 Sept- 5, 1961 J. H. GREENING ET AL 2,998,682

HONING TOOL HAVING FULL-FLOATING BODY Filed May 12, 1958 2 Sheets-Sheet 2 2,998,682 HONING TOOL HAVING FULL- FLOATING BODY John H. Greening, Oak Park, and Albin S. Czubak, Detroit, Mich., assignors t Micromatic Hone Corporation, Detroit, Mich, a corporation of Michigan Filed May 12, 1958, Ser. No. 734,520 7 Claims. (Cl. 51-1843) This invention relates to honing tools, and particularly to a honing tool having a body supported for universal movement about a center therewithin.

The process of honing embraces the concept of moving abrasive elements over a workpiece surface to first remove material to a desired depth and then to impart a smooth, accurately dimensioned finish to that surface. In the honing of cylindrical surfaces, such as cylindrical bores, a drive spindle having a honing tool drivably connected thereto is substantially aligned with the bore and is driven to reciprocate and rotate the tool within the bore. The tool generally carries a plurality of abrasive elements spaced circumferentially therearound and maintained in abrading engagement with the wall of the bore. It will be appreciated that for the production of perfectly circular cylindrical bores the axis about which the tool is rotated should be coincidental with the axis of the bore. Inasmuch as the tool is drivably fastened to the end of the drive spindle, this involves alignment of the drive spindle with the bore. In practice, however, it is extremely ditlicult, if not impossible, to maintain a precise coaxial relationship between the drive spindle and the bore. The inherent limitations of the honing machine, the positioning of the workpiece, and minor variation in distance between the different bores to be honed on a multiple spindle honing machine all present problems which can result in minor misalignment between the drive spindle and the bore. It is accordingly necessary to provide means for compensating for such minor misalignments so that the honing tool will be left free to align itself within the bore by its engagement with the bore wall.

To accomplish the above object a flexible coupling or universal joint was customarily provided between the drive spindle and the tool or between various portions of the drive spindle, which had certain disadvantages. The high drive torque which was necessary to overcome the resistance of the honing tool was transmitted through the coupling and frequently caused the coupling to bind. This produced side thrust which wore the abrasive elements unevenly and produced irregularities on the workpiece surface. When the tool was partially lifted out of a bore during its reciprocation (as it should be for uniform results) the upper end of the tool tended to gyrate or move eccentrically and produced a greater diameter at the upper end of the bore than at the middle of the bore. It is, accordingly, an object of the present invention to provide a honing tool having a body adapted to carry abrasive elements, which is capable of limiteduniversal movement relative to its driving member without developing side thrust or eccentric forces.

It is another object of the present invention to provide a honing tool having a body member carrying abrasive elements which is universally movable on a supporting surface that is independent of the bodys torque receiving connection with its driving member.

It is a further object of the present invention to provide a honing tool in which the body member carrying the abrasive elements is drivably contacted by its driving member at the middle of its length, and is free to rock about its center to align itself in and accurately follow the surface of a bore or other workpiece surface in which it is being rotated or reciprocated.

Patented Sept. 5, 1961 It is an additional object of the present invention to provide a honing tool of the above character in which the abrasive elements may be remotely adjusted in a radial direction during the honing operation to compensate for their wear or to increase the size of a bore or other workpiece being honed.

It is a still further object of the present invention to provide a honing tool which may be partially withdrawn from a bore during its rotation without tending to gyrate or move eccentrically as a result of a slightly misaligned drive spindle.

It is another object of the present invention to provide a honing tool of the above character in which the abrasive elements carried thereby tend to wear evenly and therefore permit a honing machine to be operated for a longer period of time without having to be shut down for installation of new abrasive elements.

It is another object of the present invention to provide a honing tool having a body member carrying abrasive elements which is free to float within a workpiece bore to follow the walls of the bore during its reciprocation or rotation and which is not held on a fixed axis by its connection to a drive member.

It is another object of the present invention to provide a honing tool of the above character which is sturdy in construction, inexpensive of manufacture and easily disassembled for installation of new abrasive elements or the performance of other maintenance operations.

Other objects and advantages of the present invention will become apparent from the following detailed description taken in conjunction with the accompanying drawings, wherein:

FIGURE 1 is an elevational view, partly in section, of a drive spindle and a honing tool embodying the principles of the present invention;

FIG. 2 is a sectional view of the structure illustrated in FIG. 1 taken along the line 2-2 of FIG; 3;

FIG. 3 is a sectional View of the structure illustrated in FIG. 2 taken along the line 33 thereof;

FIG. 4 is an elevational view, partly in section, of a drive spindle and honing tool illustrating another form of the invention;

FIG. 5 is a bottom plan view of the structure illustrated in FIG. 4, and

FIG. 6 is a sectional View of the structure illustrated in FIG. 5 taken along the line 6-6 thereof.

Referring now to the drawings, FIGS. 1 to 3 illustrate one form of the invention, in which a honing tool, generally indicated at 11, is rigidly connected to a hollow dr-ive spindle 13 by means of a cup-shaped nut 15. The honing tool includes a body member 17 which is generally in the form of a spool having a central radial flange 20 and an axial bore 19. The radial flange 20 has two angular recesses 21 and 23 formed on opposite sides inwardly of the peripheral wall thereof. The body 17 is supported and generally enclosed by a cage or supporting member 25 having a disk-shaped bottom portion 27 and a pair of integral, longitudinally upwardly extending posts 29 and 31 arranged on opposite sides thereof. The posts 29 and 31 areadapted to lie within the recesses 21 and 23 respectively, and are conformably shaped thereto, except that substantial clearance is provided therebetween to permit the body 17 'to rock or adjust itself universally with respect to the posts 29 and 31. As may be seen in FIG. 3, one side 33 of the recess 21 and one side 35 of the recess 23 are disposed diametrically with respect to the axis of rotation of the tool and receive the driving torque communicated from the drive spindle 13, as will hereinafter be explained. The tops of the posts 29 and 3-1 are secured to a drive adapter 37 by screws 39. The drive adapter 37 forms the upper portion of the enclosure for thebody 17 and is threaded at its upper extremity for the reception of the nut 15.

It will be seen that the drive adapter 37 and cage together surround and entrap the body 1'7, and cooperate as a drive unit for driving the body 17.

To secure the tool 11 to the drive shaft L, the lower end of the drive shaft is provided with a radially outwardly extending flange 41 abutting the upper end of the drive adapter 37 on its one side and held on its other side by an inwardly extending flange 43 formed on the nut 15. The tool 11 is thus secured against longitudinal movement relative to the shaft 13. To prevent the rotation of the tool 11 relative to the spindle 13 the upper surface of the drive adapter 37 is provided with a bore 45 to receive a pin 47 fixedly depending from the drive spindle 13.

The body 17 is provided with six circumferentially spaced slots 49, which have substantial longitudinal length and extend radially from the bore 19 to the exterior surface of the body 17. An abrasive element 51 is held within each of the slots 49 to project radially outwardly from the body 17. Each abrasive element 51 includes a bonded abrasive stone 53 encased in a backing member 55 having-notches 57 in its top and bottom for the reception of the usual garter springs 59. The body member 17 is additionally provided with a pair of vertically spaced circunncrcntially extending slots 60 and 61 to reduce the overall weight of the body 17.

Within the bore 19 of the body member 17 an abrasive element expansion member 63 is positioned for the purpose of radially adjusting the abrasive elements 51. The expansion member 63 is generally circulm cylindrical, but is provided with an upper group of spaced cam surfaces 65 sloping downwardly and inwardly and lying on the surface of a cone. A lower group of cam surfaces 67 are spaced around the member 63 beneath the surfaces 65 and also lie on the surface of a cone. The number of the cam surfaces 65 is identical with the number of cam surfaces 67, and they are disposed in vertically aligned pairs. Disposed within each slot 49 is a cam plate 69, generally in the shape of a U, and having an upper leg 71 provided with a cam surface 73 matingly engaging one of the cam surfaces 65 and a lower leg 75 provided with a cam surface 77 matingly engaging one of the cam surfaces 67. Each cam plate 69 abuttingly engages its adjacent abrasive element 51 and is operable to expand the abrasive element 51 radially outwardly against the bias of the garter spring 57. As may be seen in FIG. 2, downward movement of the expansion member 63 will cause radially outward movement of the cam plates 69 for this purpose.

The xpansion member 63 is operated by an actuating rod 79 which is disposed within the drive spindle 13 and terminates in an end 81 of reduced diameter adapted to fit within a blind bore 83 provided in the top of the expansion member 63. The bore 83 is counter-sunk at 85 to accommodate a lock ring 87 secured on the rod 79. The ring 87 is engaged by a pin 89 secured in the expansion member 63 to prevent withdrawal of the reduced diameter end 81 from the bore 83. Sufiicient clearance exists between the lower end portion of the rod 79 and the expansion member 63 to permit the body 17 to rock or pivot on the segmental spherical surfaces between the annular members 79, 101, 103 and 107 without being restricted. The rod 79 has a shoulder 91 spaced upwardly from its end 31 which compresses a coil spring 93 through the intermediary of a washer 95 as it moves downwardly. The spring 93 seats against a guide bushing 96 secured in the shaft 13 by a set screw 98 and through which the rod 79 is guided. The rod 79 is adapted to be connected to a suitable source of fluid pressure (not shown) in order to be urged in an axial direction against the bias of the coil spring 93 to expand the abrasive elements 51. When the fluid pressure is released, the spring 93 operates to lift the expansion member 63 upwardly and permit the garter springs 59 to move the abrasive elements 51 inwardly to a retracted position.

The upper end of the body member 17 is provided with an annular shoulder 97 against which an annular bearing member 99 is press fit. Matingly engaging the bearing 99 is a bearing 101 press fit in the drive adapter 37. The bottom of the body member 17 is also provided with a shoulder 102 against which an annular bearing 103 is press fit. An annular bearing 107 is press fit in the lower portion 27 of the supporting member 25 and matingly engages the bearing 103. The mating surfaces of the bearings 99, 101, 103 and 107 are all disposed on a common sphere having its center on the axis of rotation of the tool at the longitudinal midsection of the abrasive elements 51. By means of said bearings the body member 17 is supported between the supporting member 25 and the drive adapter 37 for universal movement about its center. The extent of the universal movement in any direction is dependent upon the clearance between the posts 29 and 31 and the recesses 21 and 23. To transfer torque to the body member 17 from its supporting structure, the posts 29 and 31 are provided with grooves 109 and 111 carrying torque pins 113 and 115 respectively. The pins 113 and 115 are disposed radially with respect to the body 1! and engage the body 17 along the diametrically disposed recess surfaces 33 and 35. Additionally, the pins 113 and 115 are spaced exactly 180 apart and lie on a straight line extending through the axis of the tool. The pins are disposed on the leading surfaces the posts 29 and 31 and, therefore, remain in constant driving engagement with the body 17 during rotation of the tool. Thus the torque received by the body 17 is transmitted directly through its center and the tool is perfectly free to rock or float on its segmented spherical bearings about the center of the torque transfer.

In the use of the honing tool of the present invention, the tool is first inserted in the bore with the abrasive elements 51 retracted. The rod 79 is then actuated to depress the expansion member 63 which, in turn, forces the cam plates 67 and abrasive elements 51 in a radially outward direction until the stones 53 come into contact with the work surface. The honing machine on which the tool is used is then operated to rotate and axially reciprocate the drive spindle 13. The drive adapter 37 and cage 25, being secured to the spindle 13 by the nut 15, are carried with the spindle and function as a driving unit to drive the body 13 carrying the abrasive elements 51. The axial reciprocatory movement is transmitted to the body 17 through the segmental spherical bearings 99, 101, and 107, while the torque is transmitted to the body 17 through the torque pins 113 and 115. As the pins 113 and bear against the diametrically disposed walls 33 and 35 of the body 17, the body is free to float relative to its drive unit by either rocking on the pins or sliding therealong. Suflicient clearance exists between the posts 29 and 31 and the recesses in which they lie to permit the body 17 to be maintained on the axis of the bore being honed by the stones 53 in engagement with the wall thereof and thereby compensate for any slight misalignment which might be encountered. To further stabilize and align the body 17 in the bore, a plurality of non-abrasive wiper guides 117 may be spaced circumferentially around the body 17. The guides 117 keep the body 17 aligned when the abrasive elements 51 are retracted just prior to retraction of the tool from the bore or immediately after insertion of the tool into the bore. However, the guides 117 are essentially an optional feature and may be omitted in cases where a fine surface finish is not required. During the boring operation constant pressure is maintained on the rod 79 in order to keep the stones 53 ,in abrading engagement with the wall of the workpiece bore with a predetermined pressure.

To properly finish a bore it was found that the honing tool, ideally, should be lifted out of the bore one-third of its length upon each reciprocation. Otherwise, the

upper portion of the bore would not have as much stock removed therefrom as the middle of the bore wall and variation in the diameter of the bore would result. It will be noted that when the tool of the present invention is lifted from the bore by one-third of its length, the torque pins 109 and 111 will still lie beneath the top of the bore and thus the body 17 does not tend to gyrate eccentrically at its top.

FIGS. 4, and 6 illustrate another form of the present invention having a body member 121 of a slightly different configuration and also illustrating a diflerent means for actuating an abrasive element expansion member 123. The body 121 has a central longitudinal bore 125 within which the expansion member 123 is located. In addition, the body 121 is provided with four slots 127 of substantial longitudinal length which extend radially outwardly from the bore 125 to the lateral exterior of the body 121. Four abrasive elements 129 are disposed within the slots 127 in order to project radially outwardly from the body 121. A cam plate 131 is also disposed within each of the slots 127 in abutment with the abrasive elements 129 and is slidably engaged by the expansion member 123 in the same manner as the form of the invention illustrated in FIGS. 1-3. Thus, downward movement of the expansion member 123 eltects radial expansion of the abrasive members 129. i

The body 121 is supported by a supporting member 133 having a disk-shaped lower portion 135 and four longitudinally upwardly extending posts 137A, 137B, 137C and 137D, which are-spaced 90 apart. The body 121 is provided with suitable circumferentially spaced longitudinal recesses 139A, 1393, and 139C and 139D, in order to receive the posts with substantial clearance therebetween. The tops of the posts are secured to a drive adapter 141 having a central bore 143 which is in turn non-rotatably secured to a drive spindle 145 by means of a nut 147. The spindle 145 is centrally hollow, and an actuating rod 149 extends therethrough. 'The lower end of the rod 149 is provided with a bore 151 of hexagonal cross-section in order to receive an hexagonal upper end portion 155 of a screw 153. The screw 153 extends through the nut bore 143 and threadably engages a nut 157 non-rotatably carried at the upper end of the body 121. A non-threaded lower portion 159 of the screw, having a segmentally cylindrical groove 161 formed circumferentially therearound, extends within a bore 163 formed in the upper end of the expansion member 123. The bore 163 is provided with a groove 165 adapted to lie opposite the groove 161. The screw lower portion 159 is held Within the bore 163 by means of a plurality of balls 167 which lie partially within each of the grooves 161 and 165. The screw 153 is thus free to rotate relative to the expansion member 123, yet carries the expansion member 123 with it in an axial direction as it is fed through the nut 157. The screw 153 is rotated by the actuating rod 149 and the interfitting of the bore 151 and screw upper portion 155 permit axial movement of the screw 153 relative to the rod 149 while maintaining their corotational relationship.

The body member 121 carries annular bearings 169 and 171 matingly engaging bearings 173 and 175 having mating bearing surfaces disposed on a common sphere, which bearings function in an identical manner to the spherical bearings depicted in the form of the invention illustrated in FIGS. 1-3. In addition, opposite posts 137A and 137C are adapted to carry torque pins for transmitting the driving torque to the body 121. The post 137A is provided with torque pins 177A and 177B on opposite sides thereof, which contact opposite walls of the slot 139A. The post 137C carries torque pins 179A and 17913 on opposite sides thereof, and which engage opposite walls of the recess 139C. The torque pins are longitudinally positioned at the midlength of the abrasive elements 129. If the honing tool is only driven in a counter-clockwise direction, as viewed in FIG. 5,

carry any torque pins, but rather serve to strengthen the construction of the driving unit formed by the supporting member 133 and the drive adapter 141. In view of the fact thatthe additional posts take up substantial room in the body member 121, the number of abrasive elements utilized in this form of the invention is consequently reduced from the number used in the form of the invention illustrated in FIGS. 1-3. It will also be seen that the form of the invention illustrated in FIGS. 46 does not require a hydraulic system to actuate the rod 149 but, rather, this rod may be actuated by mechanical means. It will be appreciated that both the hydraulically actuated rod illustrated in FIGS. 1-3 and the screwtype rod illustrated in FIGS. 4-6 could be used in conjunction with the body and cage structure depicted in either form of the invention.

The honing tool of the present invention, in either form illustrated, may be readily disassembled for servicing or replacement purposes. For example, in the structure illustrated in FIGS. 1-3 the nut 15 may be disconnected from the drive adapter 37 in order to remove the entire honing tool from its drive spindle 13,-and the drive spindle may thus be left in the homing machine during the servicing operation. If it is necessary to install new abrasive elements in the tool, the garter springs 57 may be removed and the abrasive elements 51 withdrawn directly from the slots 49 in which they are positioned.

While it will be apparent that the preferred embodiment of the invention disclosed is well calculated to fulfill the objects above stated, it will be appreciated that the invention is susceptible to modification, variation and change without departing from the proper scope or fair meaning of the subjoined claims.

What is claimed is:

1. In a honing tool adapted to be rotatably driven by a drive spindle, a body member adapted to carry a plurality of circumferentially arranged, radially adjustable abrasive elements and having a central longitudinal bore, an abrasive element expansion member disposed in said bore operable to radially adjust the position of the of longitudinally extending recesses formed on the op- Y posite sides thereof and a central longitudinally extending bore at the upper end thereof, a drive unit having top and bottom portions disposed above and beneath said body member and a pair of posts arranged on opposite sides thereof extending longitudinally between said portions of said drive unit within said body recesses in spaced relation thereto, torque transmitting means between said posts and said body member, bearing surfaces between said body member and said drive unit portions to permit pivotal adjustment of said body member relative to said drive unit, said body member having a plurality of circumferentially arranged slots extending radially outwardly from said bore and supporting abrasive elements therein, an expansion member disposed in said body bore having cam surfaces for radially adjusting the abrasive elements upon longitudinal movement thereof, and means 7 engageable with said expansion member at the, upper end thereof remotely operable to move said expansion member in a longitudinal direction.

3. In a honing tool, adapted to be connected to a drive spindle for rotary and reciprocatory movement, a body member having a pair of longitudinally extending recesses formed on opposite sides thereof, and a central longitudinally extending bore, a plurality of abrasive elements carried by said body member and slidably adjustable within said body member in a radial direction, a drive unit supporting and entrapping said body member for relative universal movement, said-drive unit hav ing an upper portion adapted to be secured to a drive spindle and a lower portion disposed beneath said body member, said portions being interconnected by a pair of opposite posts disposed within said body recesses in spaced relation thereto, segmental spherical bearing surfaces on said body member at the upper and lower ends thereof and segmental spherical bearing surfaces on the upper portion and bottom portion of said drive unit matingly engaging said body member spherical surfaces, said mating segmental spherical surfaces being generated about a center on the axis of rotation of said body member medially of the abrasive elements, torque transmitting means between the leading edges of said posts and said body member diametrically opposite said center, an expansion member slidably disposed within said body member bore operable to radially expand said abrasive elements, and means yieldably urging said abrasive elements in a radially inward direction.

4. A honing tool adapted to be rotated about a given axis including a centrally open body member having means for carrying a plurality of circumferentially spaced radially adjustable abrasive elements, an axially movable abrasive element expansion member disposed within the opening of said body member, a drive unit having hearing portions at opposite ends of said body member retaining and supporting said body member for limited universal movement about a center disposed on said axis, and a plurality of elongated portions interconnecting said bearing portions, and means for transmitting torque between said body member and at least some of said elongated portions at locations generally radially opposite said center.

5 The structure set forth in claim 4 wherein said bearing portions are spaced apart in an axial direction and said elongated portions extend in an axial direction.

6. The structure set forth in claim 4 wherein said means includes a pair of diametrically opposite elements between said body portion and two of said elongated portions.

7. The structure set forth in claim 6 wherein said torque transmitting means includm elements which are disposed on diametrically opposite sides of the axis of rotation of the tool and are radially opposite said center.

References Cited in the file of this patent UNITED STATES PATENTS 1,863,042 Floss June 14, 1932 2,331,523 Wacker Oct. 12, 1943 2,345,930 Fulmer Apr. 4, 1944 2,532,682 Sunnen Dec. 5, 1950 2,823,497 Brooks Feb. 18, 1958 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 2,998,682 September 5 1961 John H. Greening et ale It is hereby certified that error appears in the above numbered pat-- ent requiring correction and that the said Letters Patent should read as corrected below.

Column 5, line 32 strike out anol first occurrence;

column 6, line 31, for "homing" read honing column 8 line 21, for the claim reference numeral "6" read 1 i Signed and sealed this 6th day of November 1962,

(SEAL) Attest:

DAVID L. LADD ERNEST W. SWIDER Attesting Officer Commissioner of Patents 

